In the portable terminals using a mobile communication network for communication, there are also portable terminals having an ad hoc communication function for direct communication between portable terminals without a mobile communication network. A system designed to improve an advertisement effect by delivering advertisement information from an advertisement delivery terminal installed at a store to portable terminals in the communication range of the advertisement delivery terminal using the portable terminals and then by transmitting the advertisement information to a plurality of non-specific portable terminals in relay by means of ad hoc communication between portable terminals has been proposed (see Patent Literature 1).
Further, those disclosed in Patent Literatures 2 to 4 have been known as technologies relating to the ad hoc communication.